Unshielded, or insufficiently shielded, electronic components or electric circuits can be damaged due to arcing or short circuits. In very high voltage applications, it can be difficult to provide sufficient shielding to avoid such arcing or short circuits. For example, in a power supply for a small x-ray tube, a voltage differential of greater than 10 kV may exist between electronic components and a housing and the electronic components and housing may be separated by a distance of only about 1 cm. Potting may be used as an insulator, but such potting can break down, thus resulting in arcing or short circuits. Minor defects in the potting, including defects that cannot be visually observed, can allow such arcing or short circuits.
Shown in FIG. 7 is a prior art circuit board 11 with traces 62 and electronic components 13-14. Corners or sharp areas 73 on the components or connections to the components can have very high electric field strength if there is a large voltage difference between the corners or sharp areas 73 and a device 77. The electric field strength at such corners or sharp areas 73 can be substantially higher than the electric field strength at broader areas 74 of the components.